A Cool video of Joe Roberts.

RE: A Cool video of Joe Roberts. , posted on July 2, 2012 at 08:15:22
Tom Brennan Audiophile Posts: 5588 Joined: January 2, 2000	I want to see a video of Joe writing me a check for undelivered issues of Sound Practices.

RE: A Cool video of Joe Roberts. , posted on July 2, 2012 at 11:01:01

tomservo
Manufacturer

Posts: 6474
Joined: July 4, 2002

Sure, if it's just for looks, it doesn't matter that acoustically speaking, it can't drive a horn above it's "piston operation".

Thankfully, hifi is very largely a looks / expectation based market and not based on how sound works / propagates.

Freely radiating, the Manger driver is a pretty cool source (the best single source "in time" i have ever measured) especially at low levels where the distortion is low.

Which make me doubt the 93db/? specification. And BDS is going to kick in pretty early as well., posted on July 2, 2012 at 19:34:43

Timbo in Oz
Audiophile

Posts: 14972
Location: Canberra - in the ACT - SE Australia
Joined: January 30, 2002

It's a clever bending wave design isn't it?

I'd love to try a Manger in a sphere though. (Insufficient funds make it unlikely). Not efficient and it would need Eq of its BDS shelf plus separate bass support - probably actively driven to get low enough. reckon.

With the right size sphere, the bass bin could start at the BDS -3db point and still not blur bass voice sources.

I'm not at all taken with the grille-diffusor idea, either.

Warmest

Timothy Bailey

The Skyptical Mensurer and Audio Scrounger

And gladly would he learn and gladly teach - Chaucer. ;-)!

'Still not saluting.'

Sorry to hear that., posted on July 2, 2012 at 21:41:48
R Browne Audiophile Posts: 1429 Location: So. Cal. Joined: January 14, 2002	Maybe you should contact him and ask for the disc containing all the issues. Worth a try?

RE: Which make me doubt the 93db/? specification. And BDS is going to kick in pretty early as well., posted on July 3, 2012 at 07:30:08
Kloss Manufacturer Posts: 817 Location: WI Joined: January 25, 2012	I have built designs with Mangers I enjoyed the sound but I prefer compression drivers.

RE: Sorry to hear that., posted on July 3, 2012 at 10:31:26

TubeBuilder

I am sure he would give you a disk Tom. people go broke. Nobody is perfect I think you should get over it already. He should be knighted for his contributions to Hi Fidelity replay for the masses. I am sure glad I have my disk. I wish I had discovered SP ten years ago. Not that I know the guy only the legend. I like that he doesn't seem to take himself too seriously. I hope he doesn't kiddy fiddle or something.

I am going through you tube systems and even with the limitation of the medium it is plainly obvious that there is a lot of deluded people listening to bad sounding hiend hifi systems and some really decent sounding budget vintage systems too. I am learning a lot about the sound of different set ups. Hooking you tube up to a set of neutral near Field monitors is worth the effort I think. A lot of folks are recording with good ribbon mics too! Even Sakuma has many profession news bassed recordings to listen too. I dont know how he ever lived with his old altecs honking at him. You can hear them clearly.

SP on ebay cheap!, posted on July 3, 2012 at 10:42:47

TubeBuilder

Just incase nobody knows SP can be had from Joe off ebay for a few $ and you get posted a supa HiEnd Gold CD that will last forever of the whole SP collection. Even if you have every SP it would be easier to have the CD to use rather then getting dusty. Mine never leaves my drive. Its amassing all the info on the net that I recognize is from SP. And I appreciate all the folk that contributed to SP I am sure they did it for free.

I only wish I had a hard cover book of all the issues for traveling. oh man I remember the days when I could only get glass Audio :|

RE: Which make me doubt the 93db/? specification. And BDS is going to kick in pretty early as well., posted on July 3, 2012 at 10:46:11

tomservo
Manufacturer

Posts: 6474
Joined: July 4, 2002

“It's a clever bending wave design isn't it?”

It is cool! What it reminded me of was a Quad esl63 which if one only thinks of the surface, produces a segment of a spherical wave front also. Where the quad drives concentric rings of ESS elements driven sequentially with electronic delay, the manger does it with a wave progressing outwards physically.

While it was superb in “time” having one location over a wide frequency range and so could reproduce a complex wave shape like a square wave or musical signal, it also had a rapidly increasing distortion as the frequency fell. If I remember at 90dB at 1 meter, it had 5% THD @ 200Hz.
On the other hand, as part of a two way system it could be very good.
I would leave off the heating duct diffuser / fan blades, you have something that radiates nearly perfectly to begin with, put it naked on a large flat baffle I say haha .
Best,
Tom

RE: A Cool video of Joe Roberts. , posted on July 5, 2012 at 19:41:25

Joe Roberts
Manufacturer

Posts: 225
Location: Virginia
Joined: January 25, 2004

I'll send you a CD, Tom but...

Are you in fact sure that I cashed YOUR check?

When I saw the end drawing near I stopped ringing up orders and set aside all checks and credit card orders. I had a shoebox full of uncashed checks and credit info from about a 6 month period and I paid all operating expenses out of my pocket. The last issue cost me $22,000 to print and mail.

For a while, when I still had the old Mac database, I checked up on these claims and some people subscribed for one year, early on, and still complained that I robbed them! I can only wish!

SP, for the record, was run entirely at a loss. One year I made a few thousand dollars. That's like 50 cents an hour.

SP was essentially a ponzi scheme where incoming funds paid the printer and post office for the next issue, supplemented by the sale of my personal vintage hifi and tube collection. It would be worth most of a million dollars today.

I worked at least 100 hours a week on SP and did it all myself, with the kind assistance of my wife until she got tired of it (when we had a kid). I never paid myself a dime.

Even with free labor, that was not a workable plan. Yeah I am an idiot, but I wasn't doing this for money. What did you think we were a publishing tycoon outfit like Audio Amateur, Inc.!!?? ;op

Anyway, it has been 15 years, bro...what do I owe you the cost of a Happy Meal? Today I bought two bags of cat snacks, a loaf of bread, six padded envelopes, and a bag of mesquite charcoal and it cost more than a subscription to SP.

Are you saying you didn't get your $20 bucks worth in inspiration and knowledge? Tuition ain't free.

Are you certain that I didn't pay to send you an issue or two myself and never cashed your check? You might owe me $10! I'm not really keeping track.

If anyone should be disappointed with SP longevity, it should be me! But I'm glad I did it when I could. It was fun.

But seriously Tom, I'll send you a CD, if it will brighten your day. It has a few issues worth of unpublished material on it. PM your address.

------------------------------

Free your mind and your ass will follow -- Parliament/Funkadelic

RE: Which make me doubt the 93db/? specification. And BDS is going to kick in pretty early as well., posted on July 5, 2012 at 20:12:16

Joe Roberts
Manufacturer

Posts: 225
Location: Virginia
Joined: January 25, 2004

The whole idea of this speaker was to create a sound such that, if while it was playing nerds started talking about diffraction and stuff, somebody would yell out "Shhhh, were trying to listen to music over here!!"

RE: BDS, you realize that we wanted to shelve off the HF, right? There is no HF baffle.

Three was so much going on at that transition point to "outside the design spec" pistonic backhorn radiation that baffle step was not on the table for discussion.

Some designs are in the realm of empirical experimentation not calculation, and this was one of them.

There is no way to understand what this creation sounds like unless you've heard it. You really can't get there via photos and logic.
------------------------------

Free your mind and your ass will follow -- Parliament/Funkadelic

Joe, I have NOT forgotten when you gave me two free Russian oil caps to try {250 volt}..., posted on July 5, 2012 at 22:27:31
Cleantimestream Audiophile Posts: 5653 Location: Kentucky Joined: June 30, 2005	when I bought those 4 huge Sprague 1000 volt 2 microfarad caps from you on Epay. You are an enthusiast of the highest order. This accusation really rubs my Rhubarb, Make no mistake, there is NO call for you to defend yourself. Joe Roberts is finest kind. The Mind has No Firewall~ U.S. Army War College.

RE: Joe, I have NOT forgotten when you gave me two free Russian oil caps to try {250 volt}..., posted on July 5, 2012 at 23:24:54

Joe Roberts
Manufacturer

Posts: 225
Location: Virginia
Joined: January 25, 2004

Glad you remember that event, because I didn't!

I now recommend the type KBG 2uf caps over the MBG kind I used to like. Couldn't get KBG back then.

My response to Tom Brennan is not a question of defense but rather education. People have no idea what they were dealing with when subscribing to Sound Practices.

It was not a business per se, it was a communal effort of a bunch of non-professional freaks writing and working for free. It cost money (lots) to print and mail, so subscription money was a necessary evil.

There was no office, no staff. I published the first 6 issues on a 286 computer in a word processing program and pasted the pages up on poster board. It was like the Ben Franklin days. I did this in a one bedroom apartment in Alexandria, VA.

Later, I had a mother in law suite attached to my house in Austin which was my lab, ham shack, and publishing empire. One mac computer. I edited those mags in the middle of the night when it was quiet and the phone wasn't ringing nonstop, smoking a Willie Nelson size spliff in a bathing suit, listening to blues on 755As. Austin, you know...

There was one Italian subscriber who sent me a $20 bill every time I mailed out a magazine. I think he was paid up to Issue #60 or so. I think he understood what was going on.

I actually had no idea what I was doing but somehow it worked...for a while.

Periodical publishing is very tough to pull off. I wouldn't recommend trying it.
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Free your mind and your ass will follow -- Parliament/Funkadelic

Huh!?, posted on July 6, 2012 at 05:10:18
Timbo in Oz Audiophile Posts: 14972 Location: Canberra - in the ACT - SE Australia Joined: January 30, 2002	And Huh? again. Warmest Timothy Bailey The Skyptical Mensurer and Audio Scrounger And gladly would he learn and gladly teach - Chaucer. ;-)! 'Still not saluting.'

See the ayatollah's response above!?, posted on July 6, 2012 at 05:13:23
Timbo in Oz Audiophile Posts: 14972 Location: Canberra - in the ACT - SE Australia Joined: January 30, 2002	:-)! Now I'm a a nerd, for knowing that waveforms matter - to music. No folks it's got to be 'exciting' and JR approved. Warmest Timothy Bailey The Skyptical Mensurer and Audio Scrounger And gladly would he learn and gladly teach - Chaucer. ;-)! 'Still not saluting.'

RE: A Cool video of Joe Roberts. , posted on July 6, 2012 at 11:49:01
Tom Brennan Audiophile Posts: 5588 Joined: January 2, 2000	Sorry Joe, I was out of line.

RE: A Cool video of Joe Roberts. , posted on July 6, 2012 at 11:56:19
Joe Roberts Manufacturer Posts: 225 Location: Virginia Joined: January 25, 2004	Not a problem. Two sides to every story. My side is stranger than fiction. How could you know? Will send you a SPCD Monday as a gesture of goodwill...enjoy it! ------------------------------ Free your mind and your ass will follow -- Parliament/Funkadelic

huh?, posted on July 6, 2012 at 11:59:25
Joe Roberts Manufacturer Posts: 225 Location: Virginia Joined: January 25, 2004	Huh? ------------------------------ Free your mind and your ass will follow -- Parliament/Funkadelic

RE: Which make me doubt the 93db/? specification. And BDS is going to kick in pretty early as well., posted on July 6, 2012 at 12:52:29

Joe Roberts
Manufacturer

Posts: 225
Location: Virginia
Joined: January 25, 2004

Tried to find a pic of Dr,Manger's diffuser and was unsucessful, but I did find this.

A real estate company named Diffusion had a "manger" set-up in a Nativity display to boost holiday rentals!

http://www.prweek.com/uk/features/1127515/Digital-Nativity-theme-boosts-room-rental-site/

I'd bet that hay is good for room treatment...
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Free your mind and your ass will follow -- Parliament/Funkadelic

RE: A Cool video of Joe Roberts. , posted on September 11, 2012 at 04:18:28
Doug in Indy Audiophile Posts: 26 Location: Midwest Joined: March 21, 2007	Joe, SP made a HUGE impression on me. I had to keep re-reading each issue ten times, until I could understand maybe 15% of the content. IMHO SP is the best magazine ever produced, and all DIY'ers owe you a huge Thank You! It's nice to hear from you again. Best wishes, Doug Rice

High Efficiency Speaker Asylum

A Cool video of Joe Roberts.

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